Do all dogs urine mark inside the house?

Most dogs that are neutered or spayed at an early age do not mark in the house. Prevention is better than cure.

Male dogs that are not castrated are more likely to mark than castrated dogs.

Although male dogs are more likely to mark urine than females it is not unknown for a female dog to scent mark too. Often a female dog coming into heat or during it will mark to advertise her availability. A dominant female will also mark.

Female dogs may also urinate over a spot where another dog has urinated.

Small breeds tend to pee (mark) in the house more than larger dogs.

Two or more dogs living together in the same house may regard each other as competition and are more prone to urine marking. Urine marking can be a dominance issue. There may be no problem with one dog but when a second dog is introduced into the house then this may be the beginning of marking problems.